Not applicable
Not applicable
The present invention relates to containers for burnable coils, and in particular, to containers that provide adjustable burn rates and controlled snuffing.
Burnable coils, such as mosquito coils and incense coils, are designed to provide sustained vapor release. As they burn slowly they are susceptible to being inadvertently extinguished, thereby rendering the coil ineffective. Inadvertent extinguishing can occur when the coil does not receive enough air for burning, or when too much heat is drawn from the coil by conduction to a contacting surface.
Ordinarily, burnable coils are impaled on a spaded end of a post suitably mounted into the ground or a mounting surface. The coils are held off the ground/mounting surface and open to the air, thereby reducing the chance of inadvertent extinguishing. However, this leaves the burning end free to be touched. Moreover, the burn rate is largely affected by the rate of air flow past the coil. As such, a burning coil can be burned too quickly or extinguished by a strong wind.
Burnable coil holders have been developed in which the coils are enclosed inside a vented container. These containers shield the coil from excessive wind, are aesthetically pleasing and prevent accidental contact with the burning end of the coil. For example, U.S. Pat. No. 6,061,950 discloses a covered burnable coil holder in which the coil is mounted on a spade projecting from a base enclosed by a cover. The base has a number of small non-metallic pointed elements projecting upward to support the coil off the surface of the base (if it were to sag downwardly from the spade). The disclosure of this patent and of all other publications referred to herein are incorporated by reference as if fully set forth herein.
While a significant improvement, to extinguish a burning coil the cover had to be removed and the coil snuffed out directly. Further, if the holder was bumped accidentally, the coil might be jarred off the spade and snuffed.
Accordingly, a need still exists for an improved burnable coil holder.
In one aspect the invention provides a container for a burnable coil having a base with a coil support for mounting the coil adjacent the coil""s inward end. There is also a cover positioned on the base and having a downwardly depending hold-down alignable with the coil support. The cover also has openings for permitting the passage of air into the container. The term xe2x80x9ccover openingxe2x80x9d is defined to include both upwardly and sidewardly presented openings, as well as arrangements wherein space is purposefully left at the cover""s margin, where the cover meets the base. The floor of the base and the hold-down sandwich the coil to prevent its movement during the burning process.
In preferred forms the coil support includes an upwardly extending projection, and the cover includes a downwardly extending leg having at least one foot. The base has at least one arc-shaped slot with an enlarged area through which the foot can readily pass and a narrow area through which the foot cannot readily pass. The arc-shaped slot is positioned to allow the cover to be rotated so that, as the leg is moved toward a first end of the slot, the openings are increasingly closed and, as the leg is moved toward the opposite end of the slot, the opening is increasingly opened. Preferably, when the leg is adjacent a first end of the slot the openings are essentially completely closed and when the leg is adjacent an opposite end of the slot the opening is essentially fully opened.
The base includes a ring of upstanding tabs spaced apart by gaps, the tabs and a floor of the base defining a cavity for receiving the coil. The cover has a top surface with walls depending downwardly therefrom that are sized to fit around the ring of tabs and enclose the cavity. When the cover is fixed to the base it can rotate between a closed position in which the wall openings align with the tabs and an open position in which the wall openings at least partially align with the gaps between the tabs. This provides venting control for the container.
In another aspect a comfort contact area can be provided on the cover by outwardly bulging grip areas formed at junctions between the cover walls.
To minimize the likelihood of undesired snuffing the base can either have a spiral depression in an upper surface of a floor of the base (so that only extreme sag will lead to a contact of an outer portion of the coil with the floor) or an array of spirally disposed pointed peaks extending up from the floor of the base (to inhibit sagging without significant contact with the outer portion of the coil).
It is preferred that the cover is made of a thermoset plastic and the base is made of a thermoset plastic or a sand-filled resin. Further, it is preferred that the base has a concave bottom surface and the cover has a convex top surface. This permits the containers to be nested for compact storage and shipment.
In another aspect the invention provides a container for controlling burn rates of a burnable coil. There is a base having a coil support for mounting the coil on the base, and a cover having openings for permitting the passage of air into the container. The cover is rotatably mounted on the base so that the cover openings can be selectively opened and essentially closed by relative rotation of the cover relative to the base.
In still other forms, the invention provides a mosquito coil having an upper and a lower surface, and an opening extending between the surfaces adjacent its inward end. The opening has a Saturn-shaped cross section. xe2x80x9cSaturn-shapedxe2x80x9d is defined as describing a circle with a line extending from side to side, through its center, somewhat resembling the planet Saturn and its rings, with the rings viewed edge-on. Alternatively, there may be two openings extending between the surfaces adjacent the coil""s inward end, each opening having a different cross sectional shape (e.g. circular and elongated or square).
Thus, the present invention provides a container for a burnable coil allowing the burn rate, and thereby vapor release rate, to be easily controlled without contacting the coil. This is accomplished by rotating the cover in either direction to cause the openings to be more or less obstructed by the base.
Grip areas on the cover allow for easy manipulation of the cover as well as insulate one""s hands from the heat of the coil. Inadvertent snuffing is avoided by the raised coil support, as well as the raised peaks or depressed recesses.
The coil is firmly pinned in place against movement within the container, being held between the coil support and the downwardly depending hold-down, and the coil support also contains a portion that will insure snuffing of the coil before the hold-down feature is contacted by the burning coil, thus allowing the hold-down and the cover to be made of materials that cannot withstand the intimately applied heat of the burning zone of a burning coil.
Alternatively described, the container of the invention for a burnable coil includes a base having a coil support for mounting the coil. The container also has a cover rotatably positionable on the base, the cover having at least one cover opening for permitting the passage of air into the container, the cover and base being so constructed that a user can rotate the cover on the base to increasingly close and open the cover opening.
Alternatively, the invention may be described as a container for a burnable coil having a base and a cover positionable on the base to enclose the coil as it burns. The base has a coil support for mounting the coil adjacent an end of the coil. The coil support has an upper surface to receive a portion of the coil in directly contacting relation, the upper surface being sufficiently heat absorbing as to cause a burning coil contacting the upper surface to extinguish when the fire reaches the margin of the flat upper surface. It is not required that the upper surface be flat, although that is preferred so as to provide better thermal drain from the coil to encourage prompt extinguishment of the coil.
The foregoing and other advantages of the invention will appear from the following description. In that description reference is made to the accompanying drawings which form a part hereof and in which there is shown by way of illustration preferred embodiments of the invention. These embodiments do not represent the full scope of the invention. Thus, the claims should be looked to in order to judge the full scope of the invention.